In most shells,
aliases (10.2
, 10.3
, 10.4
)
are an easy way to shorten a long command line or do a short series of
commands.

All except the oldest Bourne-type shells have
shell functions (10.9
)
.
These are a cross between aliases and shell scripts.
They're good both for shortening command lines and for running a short or
long series of commands.

You can
simulate shell functions (10.10
)
on older Bourne shells.
These "fake functions" don't have much more power than aliases - but they're
better than nothing!